Over the past four and a half billion years, Earth
and the moon have been bombarded by interplanetary debris.
The incoming debris ranges in size from dust-sized particles
to objects the size of small planets. Following a period
of heavy bombardment that formed the early Earth and
moon, these impacts have continued at a fairly steady
rate for the past three billion years.

NASA/GSFC/USGS/JPL

An inbound asteroid approaches the Earth-moon system.

1.
Predict what would happen if twin asteroids, each 1000
meters in diameter, were to collide with Earth and the
moon. Include a description of the impact craters you
would expect to see on each body.

2. What do you think the two craters would
look like ten million years in the future?